Orthodontics is the branch of dentistry dealing with tooth and jaw irregularities and their related structures. The primary purpose of orthodontic treatment is to alter the position of an individual's teeth and jaws, and to reorient these structures in order to modify their cosmetic appearance and/or improve their function. Techniques for orthodontics have become extremely sophisticated over the years.
When considering orthodontic treatment for a particular individual, typically the individual's tooth size and jaw dimension are accepted as they are, and the orthodontist has not traditionally attempted cosmetic change based upon the individual's facial parameters. Rather, the orthodontist typically uses a wax imprint of the individual's teeth and then attempts to straighten or re-align the teeth with braces and/or other currently known orthodontic devices.
A common principal relating to what is considered “beautiful” is the universal recognition of pleasant proportion. Early Greek mathematicians recognized this, and described what has been called the “Golden Proportion” or the “Golden Ratio.” This proportion, typically indicated with the Greek letter Φ, has long been used by artists, architects, and other scholars to create aesthetically pleasing works of art and structures. In short, the Golden Proportion is a mathematical relationship between two linear distances from the division of a straight line in such a way that the shorter part (S) is to the longer part (L) as the longer part is to the whole (S+L), such that each ratio equals 0.618. That is, S/L=L/(S+L)=0.618. When this relationship applies, then the ratio of L to S is 1.618, or approximately 89/55.
The Golden Proportion has been recognized as describing an aesthetically pleasing relationship between the sizes of the frontal upper teeth when viewed from the front and has been applied by a number of scholars in making linear measurements to analyze dental aesthetics. Beyond application to the teeth, a number of researchers have noted the appearance of the Golden Proportion in measuring the linear distances between certain points on the face. For example, some consider that in an attractive face the width of the mouth ill repose is roughly 1.618 multiplied by the width of the nose.
The Golden Proportion is discussed in U.S. Pat. Nos. 5,659,625 and 5,867,588 to Marquardt, which relate to methods for analyzing facial components. U.S. Pat. Nos. 4,416,063 and 4,768,953 to Nestor et al. disclose a caliper instrument for use in dentistry that is based on the Golden Proportion. U.S. Pat. No. 6,413,085 to Lee discloses a waxing guide for forming artificial teeth that employs the Golden Proportion. The guide has markings that indicate the desired relationship for an individual's anterior maxillary teeth, and this relationship is preferably in accordance with the Golden Proportion.
While these prior art patents are useful for their intended purposes, there remains a need in orthodontics and dentistry for making cosmetic change of an individual's smile according to that individual's facial parameters, including a means to determine a suitable size and position for an individual's teeth as they relate to facial landmarks.